Common coil relay and timer

ABSTRACT

A common coil device in a dryer control circuit usable as an electromagnetic device for developing functions of both a motor and a relay. The relay function is utilized as a circuit continuity function which is normally provided as a shunt to a momentarily operated starting push button, and the motor function is utilized as a timer for intermittent pulsing of the dryer drive motor during an antiwrinkle cycle.

United 1 Inventors James I. Czech 3,001,099 9/1961 Larkey 310 209 Stevwvllk; 3,109,906 1 1 1963 Abendroth 335/186 Donald E. Janke. Benton Harbor, both of, 3,204,137 8/1965 Gardes 310/164 Mich- 3,233,135 2/1966 HD1261 ,1 310 209 1 1 pp 842,090 3,443,252 5/1969 Spinelli 335/73 Filed Primary Examiner-Harold Broome Attorneys Hill Sherman Meroni Gross and Simpson [73] Amp, mu .5, 23 Thomas E. Turcotte, James S. Nettleton, Donald W.

Thomas, Burton H. Baker, Franklin C. Harter and Gene A.

Heth [54] COMMON COIL RELAY AND TIMER 8 Clalml, .3 Ih-lwlng Figs. [52] US. Cl 335/68,

[ ABSTRACT: A common coil device in a dryer control circuit usable as an electromagnetic device for developing functions 186, 228, 190; 310/191, 209, 164; 318/35 of both a motor and a relay. The relay function is utilized as a circuit continuity function which is normally provided as a [56] CM shunt to a momentarily operated starting push button, and the UNITED STATES PATENTS motor function is utilized as a timer for intermittent pulsing of 2,487,751 I 1/1949 Buckthal 335/186 the dryer drive motor during an antiwrinkle cycle.

4 3 Hi 3 L--/.5 7 45 34 L COMMON COIL RELAY AND TIMER I BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to electromagnetic control elements, and in particular to the combination of'motor and relay functions through the utilization of the same magnetic structure.

2. Description of the Prior Art I Multi-polar, self-starting synchronous motors have been known heretofore, as well as improvements in such motors for obviating blindspot conditions to improve self-starting and in the provision of running torques which are substantially equal to the potential running torque through the negation of momentary opposing magnetic polarities.

The art further recognizes the utilization of relays for providing circuit continuity in laundry appliances upon the release of a momentarily operated push button starting switch, and the provision of an antiwrinkle cycle in dryer apparatus after the drying and cool down cycles to prevent the setting of wrinkles in clothing. Such apparatus is disclosed in US Pat. No. 3,394,465 to Donald E. Janke, assigned tothe same assignee as the present invention, wherein intermittent operation of the dryer drum by corresponding intermittent energization of the drum drive motor isprovided after the drying or heating and cooling cycles to periodically fluff clothing within the drum for short periods of time to prevent setting of wn'nkles.

SUMMARY OF THE INVENTION According to the present invention, a motor is provided which has a magnetic field structure and a rotatable magnetic armature and a movable portion of the magnetic field structure to control magnetic coupling between the field structure and the armature. The movable magnetic portion is biased in a direction to provide an air gap in the magnetic structure of the motor to prevent sufficient coupling for rotation of the armature. Movement of the movable portion to close the air gap completes the magnetic circuit for motor operation, and the movable portion is maintained in the motor operational position due to the magnetic forces thereon. Advantageously, the movable portion is coupled to a push button, the momentary push-to-start push button of a dryer, and carries a movable contact which will close and be maintained closed due to the magnetic forces on the movable portion. This magnetic structure is advantageously utilized in a dryer control circuit to replace a relay which normally provides continuity after operation of the push button and to replace circuit elements for periodically pulsing the dryer motor during an antiwrinkle cycle.

BRIEF DESCRIPTION OF THE DRAWINGS The objects, features and advantages of the invention will be readily apparent from the 'following description of a preferred embodiment thereof, taken in conjunction with the accompanying drawings, although variations and modifications thereof may be effected without departing from the spirit and scope of the novel concepts of the disclosure, and in which:

FIG, 1 is an elevational view, shown partially in section, of the common coil motor and relay according to the present .invention; I

FIG. 2 is a schematic diagram of a common coil motor and relay combined with other elements to form a dryer control circuit having an antiwrinkle cycle; and

FIG. 3 is a timing chart illustrating the operational condi- 'tions of certain timer contacts and the resulting dryer cycles for the circuit of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the drawings, a common coil motor and relay is generally illustrated at as comprising a motor housing 11 including a cup-shaped section 12 housing a coil 13 wound on a bobbin 14 having an axial bore 15 therethrough. A second cup-shaped section 16 is joined to section 12 by an intermediate wall 17 which is secured by fastening means 18. Wall 17 includes an opening 19 therein for receiving pole pieces 20 and rotatable armature 22 carried by a stationary shaft 21 extending through bore 23. A pinion gear 24 and a rotatably mounted gear 25 in driving engagement therewith provide rotational motion through gear means, generally referenced 25a to a cam 27 carried by shaft 26.

The motor structure is mounted on a frame 28 including sections 29 and 30. Section 30 carries resilient springs 31 and 32 having contacts 33 and 34 thereon, respectively. Rotation of cam 27 therefore periodically closes contacts 33 and 34 for a predetermined duration. I

The magnetic circuit of the motor incl rides a stationary section 35 disposed in bore 15 and an axially movable section 36 which is normally biased to provide an air gap 37 between it and magnetic circuit element 35. A push button 39 of insulating material has a threaded section 40 for engagement within threaded bore 41 of the outer end of magnetic circuit member 36. Fastening means such as swagging referenced 42, are provided to maintain a spring member 44 secured to the movable magnetic circuit element 36, and a spring 43 is provided between the lower side of spring member 44 and the upper cup-shaped housing section 12 to normally urge magnetic circuit member 36 away from magnetic circuit member 35 thereby providing air gap 37.

Spring member 44 carries a contact 46 for contacting a contact 47 carried by spring member 45 which is secured to frame section 29.

Normally air gap 37 is sufficient to prevent rotation of armature 22 upon the application of electrical energy to winding 13; however, movement of magnetic circuit member 36 toward magnetic circuit member 35 by depression of push button 39 provides a sufficient magnetic coupling between elements 36 and 35 to rotate armature 22 and maintain an operational magnetic circuit across a smaller air gap. Sections 35 and 36 lock up magnetically and the motors continue to run as long as winding 13 is energized, and causes cam 27 to periodically close and open contacts 33 and 34. In one application, the cam was provided with a rotation of 1/5 revolution per minute and configured to close contacts 33 and 34 for 10 seconds during each revolution.

If the air gap 37 is made sufficiently small, enough magnetic flux will be developed when winding 13 is energized to attract section 36 to section 35 by solenoid action, and to thereby close gap 37 and to allow the motor armature to begin to rotate.

The latching effect of the magnetic circuit for continuous operation of the motor also provides a latching of contacts 46 and 47 in their operated condition. It is readily apparent that while a closure of contacts 46 and 47 is illustrated in the drawings, and opening of similar contacts or a transfer circuit between contacts could also be provided in accordance with well known techniques in the relay art.

Referring now in particular to FIGS. 2 and 3, apparatus such as just described is illustrated in combination with other circuit elements to provide a control circuit for a dryer. Lines Ll, N and L2 are provided in accordance with usual practice for say 240/ volt operation. The circuit illustrates that motor 10 for operating contacts 33 and 34 is provided for connection with dryer motor 49 between lines L1 and N through timer contact 52, door switch 60 and contacts 46 and 47 of the relay section of the device. A timer motor 51 is also connected between lines L1 and N over generally the same circuit by way of timer contact 54. The drive motor 49 is coupled to rotate dryer drum 48 and includes centrifugal switch 55 for removing the starting winding thereof from the circuit upon reaching a predetermined speed of rotation.

A heating element 50 is connected between lines L1 and L2 by way of timer contacts 52 and 53 and by way of centrifugal switch 56.

To initiate operation of the dryer, the program timer is manually adjusted by a dial (not shown) so that contacts 52, 53 and 54 are closed. A switch 60 is closed by operation of the door through which the dryer is loaded and unloaded, and push button 39 is depressed to close contacts 46 and 47 which maintain their closed condition due to the aforementioned latching effect of the magnetic circuit. Closure of contacts 46 and 47 completes a circuit for timer motor 51 from line L1 to line N by way of contacts 52, switch 60, contacts 54, timer motor 51 and contacts 46 and 47. Timer motor 51 is thereby energized and begins operation to control the condition of contacts 52-54 in accordance with a preset program.

Closure of contacts 46 and 47 also provide an energizing circuit for motor by way of contacts 52, switch 60, motor 10 and contacts 46 and 47. With power so applied thereto, and with the magnetic circuit element 36 positioned to reduce air gap 37, motor 10 begins operation to intermittently close and open contacts 33 and 34; however, such opening and closing of contacts 33 and 34 is not effective to assert any control over dryer motor 49 in that timer contacts 54 are closed in parallel therewith to provide an operating circuit for motor 49 until the end ofthe cool down cycle (see FIG. 3).

Closure of centrifugal switch 56 upon the attainment of the predetermined speed of motor 49 and drum 48 causes energization of heater 50 through contacts 52 and 53 and centrifugal switch 56 all connected in series between lines L1 and L2.

At the end of the drying cycle switch 53 opens to deenergize heater 50; however, motor 49 continues to run for a period of time for a cool down cycle. At the end of the cool down cycle timer contacts 54 open to permit intermittent control of the energization of timer motor 51 and dryer motor 49 by way of the intermittent operation of contacts 33 and 34.

Upon sufficient periods of intermittent operation, timer motor 51 is effective to open timer contacts 52 to remove operating potentials from the circuit. The magnetic field of winding 13 collapses permitting spring 43 to restore magnetic circuit element 36 to its deenergized position, push button 39 and spring element 44 thereby opening contacts 46 and 47. The dryer control circuit is by the foregoing action completely deenergized.

In the preferred embodiment shown, a permanent magnet was used in the electromagnetic device. It will be readily apparent to those skilled in the art that other types of motors may be used and the absence of a showing in the drawings should not be construed as a limitation of the invention.

Generally then there has been described an electromagnetic device which is operable both as a motor and as a relay, and which device, once energized, magnetically latches in its operative condition until electrical energization thereof is removed. Further, there has been described an electromagnetic control element which may in and of itself be employed to replace a plurality of individual elements each of which have their own function. In addition, there has been disclosed a combination timing and relay mechanism for use as a control element, which mechanism may find a variety of applications in control applications. Still further, there has been disclosed the realization of a laundry appliance control circuit employing fewer components than was heretofore the practice through the utilization of a mechanism.

The embodiments of the invention in which an exclusive property or privilege we claim are defined as follows:

1. An electromagnetic control device comprisingza rotatable armature, a field winding for connection to an electrical supply, a first magnetic circuit member. connectedto said armature, a movable magnetic circuit member disposed within said field winding and movable toward andaway from said first magnetic circuit memberifor completing and maintaining a magnetic circuit whereby said armature is rotated upon completion of said magnetic circuit, and switch means carried by said movable magnetic member and operated in response to movement thereof, said switch means connected in circuit with said field winding and operable to control energization of said field winding. 1.

2. The electromagnetic control device according to claim 1 and including switch means coupled to said armature and operated upon rotation thereof.

3. The electromagnetic control device according to claim 1 and including means to bias said movable magnetic member away from said first magnetic member to normally provide an air gap therebetween to prevent operation of said armature.

4. The electromagnetic control device according to claim 1 comprising means for biasing said second magnetic member away from said first magnetic member to normally provide an air gap therebetween sufficient to prevent operation of said armature.

5. The electromagnetic control device according to claim 1, comprising camming means operatively engaging said armature and said second contact means for periodically operating said second contact means.

6. The electromagnetic control device according to claim 1, including push button means secured to said second magnetic member for manual movement of said second magnetic member toward said first magnetic member.

7. An electromagnetic control device comprising: a bobbin having a bore therethrough, a winding on said bobbin for connection to an electrical supply, a rotatable mounted armature including a first magnetic circuit member extending into said bore, a second magnetic circuit member mounted for longitudinal movement within said bore toward and away from said first magnetic circuit member for completing and maintaining an operational magnetic circuit including said winding, said new and improved control armature, said'first magnetic member, and said second mag netic member to rotate said armature upon movement of said second magnetic circuit member toward said first magnetic circuit member, first contact means carried by said second magnetic member and operated in response to movement thereof, and second contact means coupled to said armature and operated upon rotation thereof. 1

8. The electromagnetic control device according to claim 7, comprising a housing containing said bobbin, said winding and said armature, and having an aperture therein aligned with said bore, and wherein said second magnetic member extends through the aperture in said housing so that said push button is located outside of said housing. 

1. An electromagnetic control device comprising: a rotatable armature, a field winding for connection to an electrical supply, a first magnetic circuit member connected to said armature, a movable magnetic circuit member disposed within said field winding and movable toward and away from said first magnetic circuit member for completing and maintaining a magnetic circuit whereby said armature is rotated upon completion of said magnetic circuit, and switch means carried by said movable magnetic member and operated in response to movement thereof, said switch means connected in circuit with said field winding and operable to control energization of said field winding.
 2. The electromagnetic control device according to claim 1 and including switch means coupled to said armature and operated upon rotation thereof.
 3. The electromagnetic control device according to claim 1 and including means to bias said movable magnetic member away from said first magnetic member to normally provide an air gap therebetween to prevent operation of said armature.
 4. The electromagnetic control device according to claim 1 comprising means for biasing said second magnetic member away from said first magnetic member to normally provide an air gap therebetween sufficient to prevent operation of said armature.
 5. The electromagnetic control device according to claim 1, comprising camming means operatively engaging said armature and said second contact means for periodically operating said second contact means.
 6. The electromagnetic control device according to claim 1, including push button means secured to said second magnetic member for manual movement of said second magnetic member toward said first magnetic member.
 7. An electromagnetic control device comprising: a bobbin having a bore therethrough, a winding on said bobbin for connection to an electrical supply, a rotatable mounted armature including a first magnetic circuit member extending into said bore, a second magnetic circuit member mounted for longitudinal movement within said bore toward and away from said first magnetic circuit member for completing and maintaining an operational magnetic circuit including said winding, said armature, said first magnetic member, and said second magnetic member to rotate said armature upon movement of said second magnetic circuit member toward said first magnetic circuit member, first contact means carried by said second magnetic member and operated in response to movement thereof, and second contact means coupled to said armature and operated upon rotation thereof.
 8. The electromagnetic control device according to claim 7, comprising a housing containing said bobbin, said winding and said armature, and having an aperture therein aligned with said bore, and wherein said second magnetic member extends through the aperture in said housing so that said push button is located outside of said housing. 